Hey Shipwrights, Wooden Mast Question

[Nanoose]

We're STILL trying to source some wood to replace our main mast and have just connected to a local log home builder (why didn't we think of this earlier) who was also connected to S.A.L.T.S. when they were building the Robertson.

Anyway!.....(I digress!!)....
1. green or air dried?
2. straight grain, or a slight spiral? (the original mast had some spiral; the potential supplier has heard it makes a mast stronger, yet a local shipwright commented on it when he saw the mast; spiral would be less expensive)
3. we've been looking for a timber cut down to 7x7, but he has some smaller logs (8-9" tops) that we could just take, today. If he needs to cut it down, it will add a lot of labor/time/$$$....

Thanks for your collective wisdom. Deb & Dave

[Rum_Pirate]

We're STILL trying to source some wood to replace our main mast and have just connected to a local log home builder (why didn't we think of this earlier) who was also connected to S.A.L.T.S. when they were building the Robertson.

Anyway!.....(I digress!!)....
1. green or air dried?
2. straight grain, or a slight spiral? (the original mast had some spiral; the potential supplier has heard it makes a mast stronger, yet a local shipwright commented on it when he saw the mast; spiral would be less expensive)
3. we've been looking for a timber cut down to 7x7, but he has some smaller logs (8-9" tops) that we could just take, today. If he needs to cut it down, it will add a lot of labor/time/$$$....

Thanks for your collective wisdom. Deb & Dave Are you having a solid mast or a hollow one?

[Nanoose]

Solid

[Thad Van Gilder]

IVY's mast is longleaf... solid that is. I have no idea where I would get another.

Her boom was a debarked cedar tree... That worked pretty well.

-Thad

[Rob Stokes, N. Vancouver]

I was the working hands for an old fisherman who had me and a buddy make him a new set of trolling poles for an inside gulf troller. We chose cedar trees, nice and straight (grained), de-barked them when they were green (it's a lot easier) and let them dry for a year before we shaped them using planes. They were very slightly tapered and about 4.5" diameter at the base, 25' long and about 3.25" in diameter at the top.

We accidentally caught the north end of Galiano one day and dipped the rails of the boat as it pulled itself around on the line. I stopped worrying about breaking the poles after that. I also put a nice big red correction mark on the chart.

I realize these weren't spars per sei - but they sure took a load nicely and were light to raise and lower. Best of all, they were totally free. Maybe you could find something similar but already dry??

Rob

[Nanoose]

Thanks, Rob. The fellow I talked with this morning has both dried and green trees available. I'll see what some of the other guys here have to say.

[Mrleft8]

Air dried. Green will cause you months of turmoil.
And let me extrapolate..... With air dried, you basically know what condition the stick is in..... With green, it could twist, shimmy, crack, bow..... You never know.

[Nanoose]

OK...air dried.

Now, is a bit of spiral a good/OK thing, or do we go for straight?

Dave Fleming, Bob Smalser (et al)....where are you??

AND, if we just buy the tree without it being sawn square - do we just 'belt sand the h*** out of it', or cut it square/tapered ourselves first before rounding again, or what?

[Don Kurylko]

Dry. Bore a hole in one end. Stand upright. Pour as much boiled linseed oil as she will stand down the hole. Repeat! Repeat! Repeat! When it shows up at the bottom, you’re done. Then you can proceed with whittling the mast.

At least, that's the advice I once got. Apparently this will help prevent the dreaded checking that is bound to occur sooner or later with solid spars. I never did try it, but it sounds feasible.

[few3]

If only Ash were acceptable..................

[Jim Ledger]

Maybe I can help with the shaping from round question. The picture shows Sea Rovers mast, an 8" solid spar. It was shaped from a larger mast, ends cut and the diameter and taper changed. This is essentially the same as shaping from a tree.

The important thing to do is to establish control and to keep control of the shape as you proceed. This means some sort of squaring and eight siding. Resist the urge to belt it into shape by eye.

Draw the diameter and taper on a piece of clean wood. Use 4"=1' for the length of the mast and plot the diameters full size. The diameter should taper very little in the mast hoop-gaff jaw area, and then make a smooth curve to the tip diameter.Lay out the shape with a batten and nails. This way you know the finished diameter at any particular point on the spar.

The stick will have some curve to it. Align the curve in the fore and aft plane and put an arrow on the butt to indicate this.You want the curve to go foreward so that the raised sail tends to strighten things out. Some of this curve might be planed out but there might not be enough wood to remove all of it.

Begin with the stick blocked on horses, foreward or aft side up, and carefully plane a flat along the full length.Check the flat with a small level to insure accuracy.Don't remove too much wood yet. We just want to establish some sort of reference.Using this particular flat for the reference we'll square everything else from it.

Roll the stick 180 degrees and do the same on the opposite side. Use a combination square sliding on a framing square to insure that your flats are square to each other.

Roll the mast 90 degrees and do the same on each side, constantly checking with a square to keep things lined up correctly.

Now you have four flats. From here you eyeball and slowly work the four sides down to your taper dimensions. At that point an eight siding gauge will work and you proceed in the normal manner.

Good luck and if I can be of any help don't hesitate to ask.

Jim

http://pic50.picturetrail.com/VOL441/8755859/16199889/251344798.jpg

[Ian McColgin]

I'm no good at getting to eightsided by eye so I use the easy way.

First, accurate four side the timber with any required tapers aloft on the sides and front - no taper on the aft side above the partners - and any taper from partners down to the butt.

Now, measure your fattest part. You're going to make an eight-siding guage, basicly a stick with a round perpendicular near each end and two scribing points in between such that the distances are either 7-10-7 or 5-7-5. Think Pythagorous and close enough and the reason will be obvious.

So if the largest dimension is 7", an 8-1/2" span lets you put the markers 2-1/2" in from each perpendicular - 5/2, 7/2, 5/2.

Keeping the perpendiculares touching opposing faces will put the guage at an angle across the face to be marked. Drag the guage along the face you're marking. The porportions will remain correct even as the angle of the guage changes with the taper.

Once all four faces are marked, you have the correct lines to trim to - easiest with a slick or adz for rough, then plane. Even by hand, this is not a huge job.

Enjoy & G'luck

[Jim Ledger]

Here's a picture of an eight siding gauge like Ian's describing. It uses drywall screws to scribe lines instead of pencils. There are also holes to use for sixteen siding which might or might not be useful.

Anyway, if you haven't already made one try it out. There's lots of descriptions in books if you feel you need more info, but Ian's ratios are the key.

http://pic50.picturetrail.com/VOL441/8755859/16199889/251398095.jpg

[John of Phoenix]

You sure you don't want make this a bird's mouth hollow mast?
Stronger, straighter, lighter, more accurate. Tapering is much easier. Probably cheaper too.

[Nanoose]

You sure you don't want make this a bird's mouth hollow mast?
Stronger, straighter, lighter, more accurate. Tapering is much easier. Probably cheaper too.

Straighter? More accurate? How?

[Mrleft8]

Making a tapered box is very accurate, and strong. You won't have all that weight walloping around either. PLUS.................. You'll have space to run your rigging and electric up inside the mast.

[Mrleft8]

Bird's-Mouth Joinery Bits™


Picture goes here.





Historically used in the construction of masts and booms for wooden boats, the bird's-mouth joint is straightforward to make, stronger than a traditional miter and, with nesting joints, easier to glue up without shifting.

With these three cutters, it is a simple matter to make 6, 8, 12 or 16 sided hollow columns, as well as straight or tapered multi-sided planters, bowls, etc., all of which can be left multi-faceted or planed / sanded round. Generally, more sections are required for larger-diameter assemblies to keep the wall thickness to a minimum, and reduce the amount of material to be removed when rounding.

Designed to produce flush joints with material up to 7/8" thick. Thicker material can be used, but will require some dressing after glue-up. Holder included with each bit.

For better safety, this bit should be used in a router table and not used free hand.
OK.... Lee Valley..... I'm really not good at this cut and paste stuff am I?

[Nanoose]

Sorry for the duplication but Deb wanted this post here rather than on the thread with the scarph question...

We finally found a timber for our new mast. It was only about 25 miles away but it was a trick to figure out how to get it home. Yes, we probably could've had a flatbed trailer with a crane bring it to us but where's the fun in that?

In case you're curious...our timber is 32 feet and that just happens to be the aisle length in a 48 passenger school bus. Deb is a teacher and was able to get "permission" to use the bus this weekend. Here are some of the photos of trying to get it out of the bus and onto sawhorses in our driveway. Enjoy,

Dave

Sliding the timber out of the bus. I'm (Dave) on the left, my buddy Jim is to my right and Lynn, looking tres chic in his gumboots drove the bus.

http://www.imagestation.com/picture/sraid225/p66a9baea564a5d76060b9dae2b9849d4/e951f97b.jpg

Lynn and Eric lower the light end of the log...

http://www.imagestation.com/picture/sraid225/p0c8ecf5df4a3c887316c7cb2047a895e/e951fa0a.jpg

We ponder our next move...

http://www.imagestation.com/picture/sraid225/p0e5e5d52ee92caa26855c98a845d913a/e951f9e1.jpg

Lynn is about to drive down the driveway and we're debating whether we'll be strong enough to hold the log as it slides out the back (we were)...

http://www.imagestation.com/picture/sraid225/pca7b65fbe37cbc1ec24e0a93a1fd81c0/e951f96b.jpg

A few final "tweaks" to get it lined up...

http://www.imagestation.com/picture/sraid225/pb2dd3e219fbefce579d4d54e4e031ef6/e951faff.jpg

You can see there is a slight twist to the grain and few knots.

http://www.imagestation.com/picture/sraid225/p04a749cc8048cc7216521ade8ae3a63e/e951fb00.jpg

With the old mast on the left you can see we've got a bit of wood to remove

http://www.imagestation.com/picture/sraid225/p362b08243a90b7106643abd176214eb8/e951fb02.jpg


http://www.imagestation.com/picture/sraid225/p31f479c5e2808985af7faababcd52b42/e951faef.jpg

[Nanoose]

we marked off the slabs to be removed to four-side the timber. I borrowed a friends chainsaw but it only worked for about 30 seconds. To get to this point I used a reciprocating saw with a 12" blade. Slow work!

http://www.imagestation.com/picture/sraid225/p2c68da778e89cb74533b4f0f9adcf75e/e9415349.jpg

With Deb's encouragement I bought a decent chainsaw and between it and the power plane finished of the first side

http://www.imagestation.com/picture/sraid225/p8ebe6f9e7b4f10c60d49f3b849d0aabd/e9415348.jpg

I've found that trying to cut to a pencil line on weathered wood with a chainsaw is pointless. I'm using blue tape to mark the cuts.

http://www.imagestation.com/picture/sraid225/pe153d487b63b7ad8f520a3331ab454ed/e9415332.jpg

We've started the second side and I hope to have it squared be end of day tomorrow...

http://www.imagestation.com/picture/sraid225/p6ab990fe986df4b6660c6928eddf4882/e9415329.jpg

Dave

[Mrleft8]

Why are you using the heart/pith?

[Nanoose]

Ah, lefty, c'mon! Ya'all told us heart was best!!!

[Mrleft8]

Ah, lefty, c'mon! Ya'all told us heart was best!!!
"All heart, no pith"

[Jim Ledger]

Lefty, I think on a solid stick like that you don't really have much choice but to box the heart. It's been done on countless numbers of masts.

Looking good, Nanoose. Keep doing what you're doing.:cool:

[Noah]

Shipping would have been a pain, but I bet this would have worked:

http://cgi.ebay.com/ebaymotors/80-Laminated-Douglas-Fir-Mast_W0QQitemZ180126024388

[Nanoose]

My forearms are, at the moment, killing me but we've now got a roughly square timber. Next step is to make it more perfectly square and to lay out accurate tapers on all four sides. Sawdust anyone...?

Noah, I read the post on the 80' mast. Shipping would've been a real problem and that thing is massive!!! Think the member of the crew that cut into it with a sawzall is still part of the crew?

Dave

http://www.imagestation.com/picture/sraid225/pa2cb5ee6b60acc8c7c1f04692fe41155/e93b3d2d.jpg

[Jim Ledger]

If I was doing it, I'd only draw the tapers only on two opposite sides as you'll remove your lines as soon as you cut your first taper.

I'd remove wood from opposite sides and keep checking the straightness of the centerlines with a string as wood is being removed. That way, should the timber bend a bit you'll catch it while you still have enough wood left to correct things. This probably won't happen but you've probably seen wood bend in a tablesaw as a slice is taken off. The tension grown into the wood is released and the remaining portion takes a bend Just something you might want to keep your eye on.

Looking good, BTW:D

[Nanoose]

Was gone for a few days this week so no evening work on the mast. Today it poured rain so we've tarped the work area (we needed to anyway in prep for varnishing). It's amazing how long it took just to hang a couple of tarps and move the stick. It seemed to take most of the morning.

http://www.imagestation.com/picture/sraid225/pd9fbaa0b2204e81b884789468abef452/e9221034.jpg

I spent the rest of the day making sure that I've got things as accurate, plumb, square and smooth as possible before eight siding it. Once it got too dark to work outside I made the spar gauge. The math is still something of a mystery to me but I think I've the dimensions correct.

http://www.imagestation.com/picture/sraid225/p5667672bb8a2f4f5dd9ad2018ab70100/e9208cba.jpg

I'll see how it works tomorrow. I expect that I'll still need to fair some of the lines.

Dave

[Nanoose]

OK...the mast is REALLY checking as we work here. i.e. existing checks are really opening up.

What's going on? What do we do?

Thanks.

DnD

[Jim Ledger]

Don't panic. That's what solid sticks do. the checks are unavoidable and don't impair the strength in any appreciable way. Paint the stick with boiled linseed oil and work it into the checks with the brush. Don't fill the checks with anything solid.

[Nanoose]

Just spent a frantic few minutes on the web and what I could find is confirmed by what you said...shouldn't affect things structurally. Really strange that it only happens on one side of the timber though. Going to play with linseed oil now...

Dave

[Nanoose]

It's now eight sided and you can see the checks...

http://www.imagestation.com/picture/sraid225/p91f2cf1f245df554ed45ff5b1eb65401/e90fdcc1.jpg

It's starting to feel more like a mast and less like a log.

http://www.imagestation.com/picture/sraid225/pc03b16b5c411c8e4ff2cb98ea1fdcdcd/e90fdcc0.jpg

The knots are quite tight and there really aren't too many.

http://www.imagestation.com/picture/sraid225/pc8b4a1bdacb896abf227a5bcacd52d30/e90fdcc2.jpg

Boiled linseed oil going on to minimize checking.

http://www.imagestation.com/picture/sraid225/p34d985ff1e8d01fb4fc3a7b261d431a9/e90fdcbf.jpg

And once the oil is on there's no way to roll the stick without making a mess!

http://www.imagestation.com/picture/sraid225/p8479cc2d52a7fdbca78c39f8cedd42a5/e90fd922.jpg

Dave

[PeterSibley]

An excellen thread , thanks all .

If I can add something ,some years ago I felled a couple of pines for use as spars .I was worried about them developing long cracks as they dried and did a bit of research on the subject .

I found a reference to pole mast building in Sweden or Norway(?) in a an old issue of Classic Boat .Their solution to the problem is to run a long power saw cut ,the length of the green pole ,as deep as possible but no deeper than the centre .

I did it to my poles and the result was excellent .The cut opened up to around 1/2" as the pole dried over the next few years .When I want to use it I'll shape it as above then route out the cut to 1/2" ,then glue in a strip of the same material .

[Nanoose]

Question:

It is the next morning. A lot of the oil isn't being absorbed. How much time do we give it, or are we supposed to rag off after a certain number of hours.

Many thanks.

Deb (for Dave)

[Jim Ledger]

Wipe it off. You'll be planing it off soon enough. Apply more each time you stop work. It might be a good idea to thin 50/50 with mineral spirits and add some japan dryer. If the surface is too tacky to wipe put mineral spirits on the rag.

Important point. Those rags will spontaneously combust if you pile them up. The best thing to do is burn them in a safe place or keep them in a bucket of water. Don't forget.

[Nanoose]

Thanks, Jim.

[Nanoose]

More wood chips and sawdust were made this past weekend...

I cut in the shoulder for the lower mastband with a circular saw. I know it would have been oh-so shippy to used spokeshave, drawknife and chisel, but was concerned about my (lack of) experience with these tools.

http://www.imagestation.com/picture/sraid225/pa125ed01ca2bc36038ac52771335e4c2/e8f8eefc.jpg

I finished dimensioning with a power plane and cleaned things up in the corners with a small chisel.

http://www.imagestation.com/picture/sraid225/p57cf547021ca461a4d20f75d400b0cdf/e8f8ec54.jpg

Then repeated the process for the upper mastband.

http://www.imagestation.com/picture/sraid225/pc595947b746c80528a56694a60b4a808/e8f8ec55.jpg

It was sixteen-sided pretty much by eye and it is looking more and more like a proper mast. We've started sanding. I did try the inside out belt sander belt method but found that it was more effort than it was worth. We're using RO sanders and are being careful to keep them moving and work to round. We'll keep you posted.

http://www.imagestation.com/picture/sraid225/p1b415b915dcc1295b9555cdd92f237f4/e8f8ec52.jpg

Dave

[Jim Ledger]

Great! It'll be on the boat next week!:D

How's the checking situation?

[Paul Girouard]

How's the checking situation?



It should be checking , on plastic :eek: , clear plastic over head :eek: up against the house :eek: $hit if he had a oven long enought I think Dave would put'er in and turn it up to high.:eek: Ta see if he could ring the moisture out faster:rolleyes:

[Nanoose]

To every thing there is a season, and our season of hewing, sawing, scraping, planing and chiseling our mast into shape is drawing to a close. With Deb's help we finished sanding today. Tomorrow we varnish!

It took much longer to get to the right dimensions. I was quite paranoid about taking too much off and wound up, after 16-siding, about 1/2 an inch too big overall. That's a lot of wood to sand off so we finally reverted to the power plane (I REALLY LOVE THAT TOOL!). Next time I'll plane to the line...

http://www.imagestation.com/picture/sraid225/p478a402757c029c962426913e8c8e97c/e8cadc72.jpg

[George Ray]

You did a GREAT job and thanks for documenting it.

The last (only) time I had to do that job I took a different approach.
(a) Assume: the log is smooth and true but is the wrong size. We bought a pole from folks that supply utility poles so it was turned smooth and was straight.
(b) Layout stations about every 4-6 inches along the length.
(c) Use string stretched tight alongside the log as reference for desired taper
(d) Mark each station with the distance below the current surface where the surface of the desired spar resides.
(e) At each station set the marked depth on a skill saw and ring/notch the log
(f) Using a draw knife knock off the 6" chips between the rings until you get close to the bottom of the notches.
(g) Switch to a long jack place and finish the surface to final dimension.

The method I used was quick and easy but does not consider the importance of having the taper only on the the front and sides but the application was for a junk rigged Wharram cat and in that case the lack of a 'non-taper' aft face is less of an issue.

[Nanoose]

Deb has finished her gazillion coats of varnish and is going to put the final touches on the top and tenon today. The mast is tentatively scheduled to go back in sometime on Thursday. We'll post those pics too... Deb did an amazing job of varnishing...

Dave

http://www.imagestation.com/picture/sraid225/p4c508b48b6cd5ca9f76282279ce0c142/e88942e0.jpg


http://www.imagestation.com/picture/sraid225/p09fecb3ff378c334fa053a1defc54b43/e88942df.jpg

http://www.imagestation.com/picture/sraid225/pa3a81054f591e924a1f0a5d14313e203/e88942de.jpg

[rbgarr]

Gaff rig? How nice!!

[Thad]

Looks BEAUTIFUL!!!

[Jim Ledger]

May I just say how nice the mast looks.

Great job on the varnish, Deb. The gloss really shows what an excellent rounding and smoothing job was done.

Well done!:)

[Nanoose]

Heard from the rigger and he should have time tomorrow to drop in our mast...we'll take it from there with the wedges, stays, etc.

On the plus side, Deb and I were able to get the standing and running rigging back on even though I hadn't taken pictures of everything (as she had suggested 47 times). Note to self: Mast hoops go on before the stick is in place....

We're packed up, ready to go...

http://www.imagestation.com/picture/sraid225/p78102832d028a25beae922b255e7e7ce/e884d3ab.jpg

[StevenBauer]

Looking great! Don't forget your camera tomorrow. :)

Steven

[Tasybear]

I am impressed! Courage, persistence and humility, yielded a fine result!

[Lion]

Very impressive work; log to completed mast on first try in 6 weeks!

Thanks for sharing, it's the best record of this task I've seen. The ongoing interaction with the forumites as it progressed has been teriffic and all the more relevant for mugs like me as it was not being done by a professional shipwright but by one of us!

Very encouraging when a first timer tackles, shares, questions and gets a great result with humour and humility. One of the better posts I've seen. Full of admiration but not overawed as it shows us that it can be done

Congratulations & thanks, Dave and Deb.

Lion

PS: Looking forward to the stepping photos.

[boatbear]

Beautiful work Nanoose. How many kilometers / miles did you and Deb trudge, pushing tools, sandpaper, brushes etc., in the process?

Also, a belated thanks to PeterSibley for the 'sawcut down the log' trick. Nice one.

Charlie

[Nanoose]

As with most things connected to a boat, installing the mast took a bit longer than expected. We had arranged to step the new one on Thursday but it didn't happen until first thing this morning. Also par for the course was doing it all in the rain. But I'm not complaining! It feels great to get this far.

The trailer from Blanchard Rigging in Sidney was much easier than the school bus we brought home the log in...

http://www.imagestation.com/picture/sraid225/p7504e6127ad7fb6f20ba1b7ed4a05387/e87de9ba.jpg

A "Loonie" (our dollar coin) went under the mast for luck...

http://www.imagestation.com/picture/sraid225/pa308353fed12392e598a3eca7ebb8d43/e87deb78.jpg

And the new mast was hoisted by Jonathan. Deb guided it carefully through the deck (and yes we remembered to put the mast hoops on first) while I lined up down below. There was a moment when I'd thought I'd cut the tenon a bit too large but it fit quite well. The wedges were then driven and Jonathan connected the triatic stay.

http://www.imagestation.com/picture/sraid225/p784142cc2d8edff19c768421117628f5/e87deb79.jpg

We motored the half mile back to our slip and, because of the rain, have left tensioning the rig for another day. We've sorted the lines and stays but haven't pulled anything tight.

http://www.imagestation.com/picture/sraid225/p773c19e62ef6e11d219ce9800183270d/e87deb77.jpg

Thanks to everyone for your kind notes, encouragement, and support. It's been an interesting project...

Fair winds,

Deb & Dave

[StevenBauer]

Sweet. She looks a treat. I'm with Lion, great thread.

Steven